Swansea Coroner's Office has told ITV News that further tests will now be carried out on Gareth Colfer-Williams, which are expected to take six to eight weeks.
His family have raised questions about the medical care he received in the days before his death.
More top news
Calm and quiet overnight with clear skies at times. Temperatures will fall, but we should escape the frost!
A grieving mother broke down in tears as she recalled how doctors could not find out what was wrong with her son in the run-up to his death.
Carol Morse claimed her 12-year-old son Ryan dropped to just four stone but doctors failed to act, Cardiff Crown Court hears.